qt-everywhere-src-5.15.1/qt3d/src/core/resources/qframeallocator_p_p.h

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#ifndef QT3DCORE_QFRAMEALLOCATOR_P_P_H
#define QT3DCORE_QFRAMEALLOCATOR_P_P_H

//
//  W A R N I N G
//  -------------
//
// This file is not part of the Qt API.  It exists for the convenience
// of other Qt classes.  This header file may change from version to
// version without notice, or even be removed.
//
// We mean it.
//

#include <Qt3DCore/qt3dcore_global.h>

QT_BEGIN_NAMESPACE

namespace Qt3DCore {

class QFrameAllocator;

struct Q_AUTOTEST_EXPORT QFrameChunk
{
    void init(uint blockSize, uchar blocks);
    void *allocate(uint blockSize);

    void deallocate(void *p, uint blockSize);
    bool contains(void *p, uint blockSize);
    void clear(uint blockSize, uchar blocks);
    void release();

    inline bool isEmpty() const { return m_blocksAvailable == m_maxBlocksAvailable; }

    uchar *m_data;
    uchar  m_firstAvailableBlock;
    uchar  m_blocksAvailable;
    uchar  m_maxBlocksAvailable;
};

class Q_AUTOTEST_EXPORT QFixedFrameAllocator
{
public:
    QFixedFrameAllocator();
    ~QFixedFrameAllocator();

    void init(uint blockSize, uchar pageSize = 128);
    void *allocate();
    void  deallocate(void *ptr);
    void trim();
    void release();
    void clear();
    bool isEmpty() const;

    inline int chunkCount() const { return m_chunks.size(); }
    inline uchar pageSize() const { return m_nbrBlock; }
    inline uint blockSize() const { return m_blockSize; }

private:
    QFrameChunk &scan();

private:
    uint m_blockSize;
    uchar m_nbrBlock;
    QVector<QFrameChunk> m_chunks;
    QFrameChunk *m_lastAllocatedChunck;
    QFrameChunk *m_lastFreedChunck;
};

class QFrameAllocatorPrivate
{
public:
    QFrameAllocatorPrivate();

    inline void *allocateAtChunk(uint allocatorIndex)
    {
        return m_allocatorPool[allocatorIndex].allocate();
    }

    inline void deallocateAtChunck(void *ptr, uint allocatorIndex)
    {
        m_allocatorPool[allocatorIndex].deallocate(ptr);
    }

    inline uint allocatorIndexFromSize(uint targetSize) const
    {
        return (targetSize + m_alignment - 1) / m_alignment - 1;
    }

    uint m_maxObjectSize;
    uint m_alignment;
    QVector<QFixedFrameAllocator> m_allocatorPool;
};

} // Qt3D

QT_END_NAMESPACE

#endif // QT3DCORE_QFRAMEALLOCATOR_P_P_H